Architectural vs. delivered performance of the IBM RS/6000 and the Astronautics ZS-1

The paper presents a comparative performance evaluation of two novel superscalar architectures, the IBM RS/6000 and the Astronautics ZS-1. The machine architectures are presented to lay the groundwork for discussing performance issues, with a RISC architecture, the Decstation 3100, serving as a baseline architecture. Important qualitative observations are made to highlight similarities between the RS/6000 and the ZS-1. Performance measurements from running systems are presented to examine delivered performance. An analytic method of bounding machine performance is introduced to help strip out implementation related details. By comparing these performance bounds, and their component terms, to the achieved performance, the authors assess how well an application code does and how well it might do, in capitalizing on the available performance. Common sources of performance losses are revealed, areas for improvement are highlighted, and specific improvements are suggested